1. Field of the Invention
The present invention relates to a device for opening a cover and, more particularly, to a cover opening device suitable for opening a battery cover of a camera.
2. Description of the Related Art
Mechanisms ordinarily used as a mechanism for opening a battery cover of a camera are a screw type of mechanism in which a battery cover is rotated with a coin or the like, a disengagement type of mechanism using a member which is hooked and pulled by a fingernail or a coin to release a battery cover from an engaged state, and a type of mechanism using an expansible or elastic member which is integrally combined with or incorporated in a battery cover. Such conventional mechanisms for opening a battery cover are sometimes inconvenient to users in performing the operation for opening the battery cover.
A cover opening/closing device has also been proposed in which a slide knob with an engaging portion is provided on the camera body side, and in which a hook portion capable of engaging with an engaging portion of a slide knob is formed on a battery cover. This cover opening/closing device opens the cover by sliding the sliding knob and has the drawback of requiring a spring for urging the cover in the opening direction.
Japanese Patent Application Publication No. 10-90770 specification discloses a cover lock mechanism which undoes locking with an engaging member by elastically deforming the engaging member to open a cover. This mechanism has a drawback of requiring elastically deforming the engaging member by applying a force to this member.
A battery accommodation chamber of a camera is ordinarily closed with a battery cover to prevent a battery accommodated in the battery accommodation chamber from falling out of the chamber. However, if a large impact is made on the camera, for example, in the event of a fall of the camera, the battery cover may be accidentally opened to allow the battery to fall. In such a case, if the battery is lost, a new battery is set by a user and the date setting is thereby reset. A need then arises for the user to perform an unnecessarily burdensome operation for again making the date setting.
In view of the above-described circumstances, an object of the present invention is to provide a cover opening device which is capable of easily opening a cover of a camera by one sliding operation, and which prevents a battery from falling out of the camera even when the camera receives an impact.
To attain the above-described object, according to one aspect of the present invention, there is provided a device for opening a cover, having a cover opening slide knob slidably provided on the main body side, the slide knob having a cam follower, and a cam groove formed on the cover supported on the main body side so as to be able to open and close, the cam groove being capable of fittingly receiving the cam follower. The cam follower is fitted in the cam groove to engage the cover with the camera body. When the cover opening slide knob is slid, the cam follower is thereby moved in the cam groove to force out the cover in an opening direction by the action of the cam groove. According to the present invention, when the operation for sliding the cover opening slide knob is performed, the cover is forced out in the opening direction by the action of the cam groove to be opened.
Also, in the present invention, the above-described cover is a battery cover capable of opening and closing a battery accommodation chamber of a camera by turning on a hinge shaft. A battery having the shape of a cylinder or a rectangular block and having an electrode projecting from one of its end surfaces is accommodated in the battery accommodation chamber. A detachment-preventing rib is provided on the camera body at the side corresponding to the projecting electrode of the battery. The rib is formed in a place corresponding to the direction of opening of the battery cover to prevent the battery from springing out in the direction of opening of the battery cover.
Thereby, according to the present invention, the detachment-preventing rib is provided at the side of the battery accommodation chamber corresponding to the plus terminal of the battery, and the rib is formed in a place corresponding to the direction of opening of the battery cover, thereby preventing the battery from springing out of the battery accommodation chamber even when, for example, an impact caused by a fall of the camera is made on the camera.
Since no rib portion is formed in a place corresponding to the direction of insertion of the battery, there is no interference with loading and unloading of the battery.